Paper machine sectional drive



Jan. 1, 1946. L. HORNBOSTEL PAPER MACHINE SECTIONAL DRIVE 5 Sheets-Sheet 1 Filed March 25, 1943 Til "Em a? Awro //o,e/vaasTE/ 1943 5 Sheets-Sheet 2 Filed Marqh 25,

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Jan. 1, 15946. L. HOIQNBOSTEL 2,392,149

PAPER MACHINE SECTIONAL DRIVE LL 0 r0 Hoe/vs 0s TEL Jan. 1, 1946. 1.. HORNBOSTEL PAPER MACHINE SECTIONAL DRIVE Filed March 25, 1943 5 Sheets-Sheet 4 Jan. 1, 1946. 1.. HORNBOSTEL PAPER MACHINE SECTIONAL DRIVE 5 Sheets-Sheet 5 Filed March 25, 1943 PAPER MACHINE SECTIONAL DRIVE Lloyd Hornbostei, Beloit, WI, assignor to Beloit Iron Works, Beloit, Win, a corporation ofWiscousin Application March 25,1943, Serial No. 480,434

12 Claims. (01. 'u-zsc) This invention relates to drive units for machines whereby various sections of the machine can be driven at different speeds from a single prime mover.

Specifically, the invention relates to a mechanical drive for paper making machines.

The transmission of power from a prime mover to a paper making machine requires installations which provide a means of altering the relative speeds of various sections of the machine to accommodate the variations in expansion and contraction of paper passing through the machine for insuring the necessary draw" between one section and another, as well as to provide for the speeding up of paper machine rolls which have been reduced in diameter from their original sizes as by regrinding and boiling operations. Heretofore, slight ditlerences in speeds of the various sections of the machine have been accomplished by use of cone pulleys and belt drives from a single line shaft for driving right angle gear units which units drive the inshaits to the machine sections. Such cone pulley and belt drives require appreciable space, involve the use of many bearings, and require wearable belts.

In accordance with this invention the heretofore necessary cone pulleys and belts are entirely eliminated and the units of this invention will not only replace such pulleys and belts, but will also avoid the necessity for additional right angle gear units.

According to this invention a small compact mechanical drive receives the main line shalt therethrough and is positioned at each section oi the machine to transmit power from the line shaft to the machine sections at the desired speed and in the desired direction. The units of this invention include a swing gear inshaft drive arrangement accommodating differences in levels of the various inshaits of the machine sections so that direct coupling between the machine section inshafts and the driving shafts of these units is possible even when the inshaits are at difierent levels at the various sections of the machine.

The units of this invention also include a symmetrical difierential drive having one side driven at substantially the same speed as the line shaft, and the other side driven at a slow speed, thereby making possible the use of small and compact parts. This difierential drive acts both as a speed reducer and as a power transmitter capable of being readily controlled by a speed changer to deliver power at the desired speed. The differential drive eliminates the necessity for a complicated multi-gear layout.

The units of this invention also include an ex temally mounted clutch which is readily accessible for inspection and repair. All other powertransmitting parts oi the unit are enclosed in a casing.

A speed changer is provided in the casing and is adjustable from outside of the casing for regulating the speed of the inshaft driven by the unit relative to the speed of the line shaft driving the unit. The parts are arranged so that only a very small amount of power goes through the speed changer. The speed changer is directly connected through gearing with the line shalt so that it can run at high speed.

The inshait driver of the units of this invention can be rotated in either direction by shitting of a single gear in the unit. Thus standard units of this invention are readily adapted for driving all sections of a paper making machine irom a single line shaft even though some sections must be driven in the opposite direction relative to other sections. 7

It is, then, an object of this invention to pro vide a compact, efllcient mechanical drive unit adapted for paper making machinery. I

A further object of the invention is to provide a mechanical drive adapted to deliver power emciently from a prime mover at a selected level and in a selected direction.

A. further object of the invention is to provide a clutch-controlled mechanical drive unit adapted to receive a line shalt therethrough and including a speed changer device and a power delivery arrangement enclosed in a casing separate from the clutch.

A still further object of the invention is to provide a variable speed mechanical drive unit for paper making machines wherein about ninety percent of the power is directly transmitted to the power delivery end thereof while about ten percent of the power passes through a manually adjustable speed changer and is added to the direct power.

A still further object of the invention is to provide a mechanical drive adapted for paper making machines including a speed changer which receives therethrough only from eight to ten percent of the power input to the unit.

A further object oi the invention is to provide a paper machine mechanical drive unit including a simplified differential drive acting both as a speed reducer and a controlled speed transmitter.

A further object of the invention is to providea differential drive unit having one'side driven at the speed of a prime mover antktlie' other side thereof driven at a selected slow speed to control the power delivery speed of the unit.

A still further object of the invention is to provide a paper machine sectional drive unit having a swingable gear casing adapted to be positioned at a desired level for direct coupling of the delivery shaft of the unit with an inshaft of the paper machine.

other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of preferred example only, illustrate one embodiment of the invention.

n the drawings:

Figure 1 is a perspective view of a sectional drive unit of this invention.

Figure 2 is a longitudinal vertical cross-sectional view. with parts in elevation, of the drive unit of this invention.

Figure 3 is a horizontal cross-sectional view, with parts in top plan, taken along the line III-III of Figure 2.

Figure 4 is a vertical cross-sectional view, with parts in elevation, taken along the line IV-IV of Figure 3.

Figure 5 is a fragmentary side-elevational view taken along the line VV of Figure 4.

Figure 6 is a vertical cross-sectional view, with parts in elevation, of the speed changer taken along the line VIVI of Figure 4.

As shown on the drawings:

In Figures 1 to 5 inclusive the reference numeral l2 designates generally a sectional drive or mechanical drive unit according to this invention. The unit III has a main base frame II with a mounting flange therearound as best shown in Figure 1 for securing the unit on the floor, for example, on the rear side of a paper makiim machine. The frame I I includes an upstanding pedestal l2 at one end thereof carrying a bearing housing IS. A box or casing I4 is formed integral with the base on the end thereof remote from the pedestal l2. This box 4 has a removable side plate l5 covering an opening in a side wall thereof. The box has an open top closed by a dome-like cover l2 which cover in turn has a removable inspection plate I! on the top thereof.

As best shown in Figure 2 the box l4 has a vertical partition wall l2 therein with apertures i2 and therethrough. The end wall of the box |4 adjacent the pedestal |2 has apertures 20 and 2| therethrough. The other end wall of the box remote from the pedestal l2 has apertures 22 and 23 therethrough. As shown in Figure 3, the front and rear side walls of the box l4 have aligned apertures 24 and 25 therethrough.

A main line shaft 25 extends longitudinally through the entire unit l0 and is rotatably mounted in a bearing 21 carried by the bearing housing l3 on the pedestal l2 and in a bearing provided. in a bearing housing 22 secured on the outside of the box l4 around the aperture 22 as best shown in Figure 2.

A hollow shaft 22 is freely disposed around the main shaft 22 and is rotatably supported in the unit III on a bearing 22 carried in the aperture 20 and in a second bearing 2| carried in the aperture 22. The hollow shaft 22 is thus rotatably mounted'in the unit l0 and extends from the bearing 3| through and beyond the bearing 32 to terminate in the space between the box and the pedestal I2.

A clutch 22 has the driving part 22 thereof keyed to the line shaft 22 together with a driven 22 includes a series of friction disks 25 slidably splined to the driving part 22 alternating with a series of shoes 22 slidably splined to the driven part 24. The shoes 22 can be urged into friction engagement with the disks 25 to couple the parts 22 and 24 of the clutch, thereby driving the hollow shaft 22 from the line shaft 22.

The hollow shaft 22 passes freely through the aperture 2 in the partition wall l2.

As also shown in Figure 2, a differential unit shaft 21 is rotatably supported in the box l4 on a bearing 22 carried in a housing mounted in the aperture 22 of the partition wall l2 and in a bearing provided in a housing 22 mounted in the aperture 22. A differential spider 42 is keyed to the shaft 21 between the bearing supports for the shaft and has bevel gears 4| rotatably mounted around the end portions thereof on bearings 42. A hollow shaft 42 is rotatably mounted on bearings 44 around the shaft 21 and has a beveled gear 45 on an end thereof meshing with the gears 4|. A second hollow shaft 45 is rotatably mounted around the shaft 21 on bearings 41 and has a bevel gear 42 on the end thereof also meshing with the bevel gears 4|.

A gear 42 secured on the hollow shaft 22 meshes with a similar sized gear 52 secured on the shaft 42. The shaft 43 is thus driven from the shaft 22 at the same speed as the shaft 22.

A gear 5| is secured on the hollow shaft 42 of the differential unit for a purpose to be hereinafter described.

A bevel gear 52 is keyed on the end of the shaft 21 which projects beyond the partition Plate I8.

The bevel gear 52 meshes with a mating bevel gear 52 on a transverse shaft 54 best shown in Figure 3. This shaft 54 has one end thereof rotatably carried in a bearing 55, which bearing 55 is mounted in a housing carried in the aperture 24.

A gear casing 55 has a hollow circular neck portion 51 projecting into the opposed aperture 22 and carrying a bearing 52 for rotatably supporting an intermediate portion of the shaft 54. The shaft 54 projects into the gear casing 52 and carries a spur gear 52 on the end portion thereof meshing with a large gear 22 on the power delivery shaft 5| of the unit. This shaft 2i is rotatably mounted on bearings 22 carried in the casing 52.

As shown in Figures 3, 4 and 5, the back face of the casing 55 has an arcuate pad 52 thereon while the front face of the box I4 and cover II have laterally projecting lugs 54 extending into contact with this pad 52. These lugs 54 are internally tapped. The casing 55 is swung in the aperture 25 to position the power delivery shaft 5| at the desired leveland holes are then drilled through the back face of the casing in alignment with the tapped lugs 54. Bolts 55 are then inserted through the holes and threaded into the top lugs 54 for holding the casing at the desired level. This arrangement makes possible the uniform production of drive units which can be readily arranged so that their delivery shafts will be at the proper levels to meet the particular installation requirements.

As shown in Figure 2, a gear 22 is secured on the hollow shaft 22 adjacent the gear 42, and as shown in Figures 3 and 4, drives a larger gear 5'! secured on the drive shaft 22 of a speed changer unitgesignated generally by the reference numeral The speed changer unit 68. as best shown in Figure 6, is mounted in a casing 10 which rotatably carries the shaft 68 together with a second changer 68. The arrangement is such that if shaft 46 were held stationary by gear II, and gear 60 drove shaft 43 at, say, 1000 revolutions per minute, differential unit shaft 31 would be driven at 500 revolutions per minute, or half the speed of shaft 43. Now, since gear 5| is always driven slowly relative to gear 60, the differential unit acts as a speed reducer without the necessity Link arms are pivotally supported interme- 11 having right and left hand threaded portions 18 and 18 respectively receiving the bosses 16 thereon. A hand wheel 80 is secured on the rod 11 on the outside of the main casing box l4 as shown in Figure 350 that the speed changer can be adjusted from outside of the unit I. Rotation of the hand wheel 80 in one direction will draw the beveled wheel flanges 13 toward each other while separating the wheel flanges 12 thereby causing the band 14 to ride further inwardly from the periphery of the wheel flanges 12 than from the peripheries of the wheel flanges 13. As a result, the shaft 1| will be rotated at a slower speed than the shaft 68. In this manner the speed of the shaft 1| can be regulated relative to the speed of the shaft 68.

The shaft 1| drives a gear 8| meshed with a gear 82 on a stub shaft 83 as best shown in Figures 3 and 4. This stub. shaft 83 is rotatably supported in a bearing 84 carried by the partition wall |8 of the box i4. A gear 85 is also secured on the stub shaft 83 and meshes with the gear 5| on the hollow differential shaft 46.

As shown in Figures 2 and 3, the aperture 2| in the box l4 does not support a bearing and is merely closed with a cover plate 2la. This cover plate 2|a can be removed for inspection of the position of the bevel gears 52 and 63. As shown in Figure 3, the bevel gear 53 can be switched from the position shown in solid lines to the position shown in dotted lines for reversing the rotation of the power delivery shaft 6|. -Thus, changing the position of only one gear 53 reverses the direction of rotation of the power delivery shaft of the unit of this invention and makes possible the production of standardized units for all installations.

In operation, power from a prime mover (not shown) drives the line shaft 26. When the clutch 32 is actuated so as to couple the driving and driven parts 33 and 34 thereof, the hollow shaft 28 is driven at the same speed as the line shaft 26. This shaft 28 will drive the gear 45 of the differential unit 31 through the gears 48 and 50, and the shaft 43. The differential unit is symmetrical so that the gear ratio through the dif ferential between gears 50 and 5| is the same. Since the gears 48 and 50 are of the same size, a l-to-l gear ratio exists between shaft 29 and shaft 43 of the differential unit. One side of the differential unit is thus driven at the same speed as the prime mover, viz., shafts 26 and 28.

The other side, viz., shaft 46, of the differential unit is driven by gear 5|. This gear 5| is driven at a selected slow speed through a double reduction'of gears (gears 85, 82, and 8|) by the speed for a heavy worm and wheel drive or other strong gear reduction drives capable of transmitting heavy loads. The arrangement cuts down the number of gears and heavy working parts heretofore required in speed reducers.

In addition to its function as a speed reducer, the difierential unit serves the dual function of accommodating differences in speed so that the power delivery shaft 6| may be driven at a selected speed relative to the speed of the line shaft 26 as determined by the speed changer 68.

The speed changer 68 is driven by the shaft 28 through the gears 66 and 61. This speed changer is then regulated by a manipulation of the hand wheel to drive the shaft 1| thereof at a desired speed and. this shaft 1| will drive the differential shaft 46 at a slow speed through the double reduction gears 8|, 82, 85, and 5|. The slow driven differential shaft 46 actuates the differential gears 4| and the shaft 31 is driven at a reduced speed relative to shaft 28 determined by the speed changer 68. The shaft 31, in turn, drives the power delivery shaft 6| through the bevel gears 52 and 53, shaft 54, gear 58, and gear 60.

Therefore, the power delivery shaft 6| can be driven at any desired speed relative to the speed of the line shaft 26 by manipulation of the hand wheel 80 for setting the speed changer.

Now, since the differential unit is symmetrical, the twisting effort on gears 50 and 5| to turn shaft 31 against a load is the same. Therefore, the relative amount of power put into the differential unit through gears 50 and 5| is directly proportional to the speeds at which these gears are driven according to the formula:

Torque (twisting effort in ft.

As explained above, gear 50 is driven at the same speed as the line shaft 26, but gear 5| is back geared down to the speed changer 68, through a double reduction of gears so that it is driven very slowly. Because of this arrangement, only about 10% of the power input to shaft 31 comes through the speed changer 68 while about of the power input to shaft 31 comes direct from the line shaft 26 and hollow shaft 28. As a result, the differential unit can be small and compact.

The clutch 32 connecting the hollow shaft 23 with the line shaft 26 can be of any suitable construction, but a compressed air-operated multiple disk clutch is preferred since such a clutch can be controlled from a remote point.

In installing the units of this invention on a paper making machine one unit is mounted at the rear side of the machine adjacent each inshaft to the machine. The line shaft then passes through all of the units and the units are selectively operated through their clutches 32 at adjustable speeds determined by manipulation of their hand wheels 80. If any unit must rotate an inshaft of the paper machine in a direction opposite to other units, such reverse rotation can be obtained by changing the position of the gear If as shown in Figure 3.

.It will. of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims,

I claim as my invention:

1. A mechanical drive comprising a hollow drive shaft adapted to receive a line shaft therethrough, a clutch adapted to selectively connect the drive shaft with a line shaft received therethrough, a differential unit having one side thereof driven by said hollow shaft, a" speed changer driving the other side of said differential unit, means driving said speed changer from said hollow shaft, a differential shaft driven by said differential unit, a transverse shaft driven by said differential unit shaft, a gear casing swingable about said transverse shaft, a power delivery shaft rotatably mounted in said gear casing, gears in said casing connecting said transverse shaft with said power delivery shaft, said power delivery shaft adapted to be positioned at a desired level by swinging said gear casing about said transverse shaft, and said speed changer unit adapted to be adjusted for controlling the speed of said power delivery shaft relative to the speed of said hollow drive shaft.

2. A mechanical drive comprising a drive shaft, a symmetrical differential unit having opposed driven sides, a speed changer driven by said drive shaft, means driving one side of said differential unit from said drive shaft at substantially the same speed as the drive shaft, means driving the other side of said differential unit from said speed changer at a slow speed relative to the drive shaft and relative to the speed changer drive, a power transmission shaft driven by said differential unit at a speed determined by the speed changer, said means driving one side of the difierential unit from the drive shaft transmitting about 90% of the power from the drive shaft to the power transmission shaft, and said speed changer driven by the drive shaft together with said means driving the other side of the differential from the speed changer transferring about 10% of the power of the drive shaft to said power transmission shaft.

3. A mechanical drive unit comprising a frame adapted to be mounted on a' floor adjacent a machine and receive a line shaft therethrough, a hollow drive shaft rotatably carried by said frame around said line shaft, a clutch having a driving part keyed to said line shaft and'a driven part keyed to said hollow drive shaft for selectively connecting the line shaft and hollow drive shaft, a differential shaft rotatably mounted on said frame in spaced parallel relation from said drive shaft, a spider secured on said differential shaft, beveled gears rotatably mounted in spaced opposed relation around said spider, a first beveled gear unit rotatably mounted around said differential shaft in meshed engagement with the spider carried beveled gears, a second beveled gear unit rotatably mounted around said differential shaft on the opposite side of said spider in meshed engagement with said spider carried beveled gears, gears connecting said first beveled gear unit with the said drive shaft for driving said first unit from said drive shaft, a speed changer unit mounted on said frame having a drive shaft and a driven shaft with means therebetween controlling the speed of the driven shaft relative to the drive shaft, means connecting said hollow drive shaft with the drive shaft of the speed changer, means connecting the driven part of the speed changer with the second beveled gear unit, a beveled gear secured on said differential shaft, a power transfer shaft at right angles to said differential shaft, a beveled gear on said power transfer shaft driven by said beveled gear on the differential shaft. a casing swingably mounted on said frame for rotation about said power transfer shaft, a power delivery shaft rotatably mounted in said casing, a gear on said power transfer shaft in said casing, and a gear on said power delivery shaft in said casing meslzing' with said gear on the power transfer shaf 4. A machine sectional drive unit which comprises'a frame having an upstanding pedestal at one end thereof and a closed box at the other end thereof in spaced relation from said pedestal, a bearing carried by said pedestal, an aligned bearing carried by said box, a main drive shaft projecting through said box and rotatably supported in said bearings, a hollow drive shaft surrounding said line shaft in said box and projecting into spaced relation from said pedestal, bearings carried by said box rotatably supporting said hollow drive shaft, a clutch between said pedestal and said box having a driving part connected to said line shaft and a driven part connected to said hollow drive shaft for selectively driving the hollow drive shaft from the line shaft, a differential shaft rotatably mounted in said box, a differential unit having opposed gears rotatably mounted on said differential shaft, a spider secured on said differential shaft, gears rotatably carried by said spider meshing with said opposed gears, a power transfer shaft rotatably mounted in said box at right angles to said differential shaft, said power transfer shaft pro- .iecting to the outside of said box, connecting gears joining the differential shaft and the power transfer shaft for co-rotation, one of said connecting gears being shiftable on its shaft to drive the power transfer shaft from the differential shaft in either direction, a gear casing swingably mounted on the outside of said box receiving the projecting end of the power transfer shaft therein, a power delivery shaft rotatably mounted in said gear casing, means for securing said gear casing to said box at a selected level, gears in said casing connecting said power transfer shaft and said power delivery shaft for co-rotation. a speed changer unit in said box driven by said hollow drive shaft and driving one opposed gear of the differential unit, and gears directly connecting said hollow drive shaft with the other opposed gear of the differential unit whereby said differential shaft will be driven at a speed relative to the hollow drive shaft controlled by the speed changer.

5. A mechanical drive unit comprising a main frame defining a hollow box, a hollow drive shaft extending through said box and rotatably carried thereby, said drive shaft adapted to receive a line shaft therethrough, a clutch for driving the hollow drive shaft from an inserted line shaft, a differential shaft rotatably mounted in said box in spaced parallel relation to said hollow drive shaft, first and second differential gears members rotatably mounted around said differential shaft, a spider secured to said differential shaft, gears rotatably carried by said spider meshing with said first and second differential gear members, a gear secured on said hollow drive shaft in said box, a similar sized gear secured on said first differential gear member meshing with said hollow drive shaft gear, a speed changer unit in said box, means connecting opposite sides of said speed changer unit with said hollow drive shaft and said second differential gear unit for passing only a small amount of power from the drive shaft through the speed changer, means proiecting to the outside of said box for adjustin said speed changer, a power transfer shaft rotatably mounted in said box at right angles to said differential shaft and having an end project-- ing to the outside of said box, a beveled gear secured on said differential shaft, a. second beveled gear secured on said power transfer shaft meshing with said beveled gear on the differential shaft, said second beveled gear adapted to be positioned on opposite sides of the differential shaft carried beveled gear to drive the power transfer shaft in opposite directions, a gear outside of said box on the projecting end of said power transfer shaft, a second gear outside of said box meshing with the power transfer shaftzcarried gear, and a power delivery shaft driven by said second gear, said second gear being rotatable about the power transfer shaft carried gear toposition the power delivery shaft at a desired level.

6. Apparatus adapted for driving a section of a paper machine from a line shaft at a predetermined speed relative to the speed of the line shaft which comprises, a main frame adapted to receive a line shaft therethrough, power transfer means mounted on said main frame adapted to be driven by said line shaft, said power transfer means including a differential unit, a differential shaft, and a speed changer controlling the speed of the differential shaft, a power delivery shaft driven from said differential shaft adapted to be coupled with a section of a paper machine, a bearing support for the power delivery shaft, a pivot for said bearing support spaced radially therefrom, a pivot support on the main frame swingably carrying the bearing support, and means for selectively securing the bearing support to the main frame for positioning the power delivery shaft at a desired level whereby the line shaft level need not be changed to'drive inshafts to the paper machine located at different levels.

7. A mechanical drive unit comprising a drive shaft, a differential unit having first and second driven sides and an intermediate driving part, a speed changer, a power delivery shaft driven by said differential unit, gears driven by the drive shaft arranged to drive the first side of the differential unit at the same speed as the drive shaft, and reduction gears connecting the speed changor with the second side of the difl'erential unit for driving said second side of the differential unit at a much slower speed than the drive shaft and the speed changer, said gears driving the first side of the differential unit transmitting about 90% of the power from the drive shaft, and said reduction gears driving the second side of the differential unit transmitting about of the power from the drive shaft, whereby the speed changer is not subjected to heavy loads.

8. Apparatus adapted for driving a machine section at a controlled speed slower than the speed of a prime mover which comprises a prime mover driven main drive shaft, a differential unit having first and second driven sides, gears driv- -ingly connecting the first side with the main drive shaft to drive the first side at substantially the same speed as the main drive shaft, a speed changer unit having a drive shaft geared to the main drive shaft to rotate at a slightly slower speed than the main drive shaft, said speed changer unit having a driven shaft selectively driven from the drive shaft thereof at a selected decreased speed relative thereto, reduction gears drivingly connecting the driven shaft'of the speed changer unit with the second side of the differential unit and arranged to rotate said second side of the differential unit at a controlled speed materially less than the speed of said speed changer driven shaft, a differential shaft driven by said differential unit at a speed controlled by said speed changer, a power transfer shaft driven by said differential shaft, and a power delivery shaft driven by said power transfer shaft and arranged to swing relative to the power transfer shaft for changing the level thereof.

9. A mechanical drive comprising a driver, a differential having first and second driven sides and a driving shaft, a speed changer, gears connecting the driver with the first side of the differential arranged to transmit most of the driving torque from the driver to said first side of the differential, reduction gears connecting the driver with the speed changer to drive the speed changer at slower speeds than the driver, additional reduction gears connecting the speed changer with the second side of the differential to drive said second side at a materially lower speed than the speed of the driver and the speed of the speed changer, and a power delivery shaft driven by said driving shaft of the differential, whereby most of the driving torque from the driver is transmitted to the delivery shaft through the differential and gears connecting the driver with the first side of the differential while said speed changer transmits only a small amount of the driving torque but controls the ultimate speed of the power delivery shaft.

10. A machine section drive comprising a main frame, aligned bearings carried by said main frame at a fixed level, a driver rotatably supported on said frame in said bearings, a secondary frame swingable on said main frame about a pivot, a power delivery shaft rotatably carried by said secondary frame to rotate about an axis radially offset from the pivot, means for selectively fixedly connecting the main and secondary frames to position the power delivery shaft at a desired level, said driver and power delivery shaft being at right angles to each other, and means carried by said main and secondary frames for transmitting ower from the driver to the power delivery shaft irrespective of the selected level for the power delivery shaft.

11. A mechanical drive comprising a driver, a differential having first and second driven sides and a driving shaft, a speed changer, means connecting the driver with the first side of the differential arranged to transmit most of the driving torque from the driver to said first side of the differential, reduction means connecting the driver with the speed changer to drive the speed changer at slower speeds than the driver, additional reduction means connecting the speed changer with the second side of the differential to drive said second side at a materially lower speed than the speed of the driver and the speed of the speed changer, and a power delivery shaft driven by said driving shaft of the differential, whereby most of the driving torque from the driver is transmitted to the delivery shaft through the differential and said means connecting the driv- 6 guano er with the first side of the diflerential while saidspeedchanzer tra'nsmitsonlyasmall amount of the driving torque but controls the ultimate speed of the power delivery shaft.

12. A machine section drive as claimed in claim 11 further comprising a main. frame, alimed manual-meaty said main frame at a fixed level, a driver rotatably supported on said frame insaidbearinza, aseeondaryframe awinzable on said main frame about a pivot. a power delivery shaft rotatably carried by said secondary frame torotateaboutanaxisradialiyoifsetfromthe pivot, means for selectively fixedly connecting the main and secondary frames to position the power delivery shaft at a desired level, and means carried by said main and seomdary frames for transmitting power from the drlverto the power delivery shaft irrespective of the selected level for me power delivery shaft.

' LLOYD HORNBOBTEL. 

